Force Password Change First Time Login

Hi,
I’m trying to redirect users the first time they login so they can change passwords to a cleaner one than what they receive in the register email. In functions.php I have:

//redirect on first login
function redirect_password_profile_update($user_id, $old_user_data) {
    $user = new WP_User( $user_id );
    if( $user->data->user_pass != $old_user_data->user_pass) {
        //password has changed
        update_metadata("user",$user_id,"changed_password",true);
    }
}
add_action("profile_update", "redirect_password_profile_update", 10, 2);

function redirect_password_login_redirect($redirect_to, $url_redirect_to = '', $user = null) {

    if( isset($user->ID) ) {
        $changed_password = get_metadata("user", $user->ID, "changed_password",true);
        if( $changed_password != true ) {
            return get_bloginfo('url') . "/wp-content/themes/xchange12/change-password.php/";
        } else {
            return $redirect_to;
        }
    }
}
add_filter('login_redirect', 'redirect_password_login_redirect',10,3);

function redirect_password_password_reset( $user ) {
    //password has been reset to a random one. so the changed_password meta data should be reset as well
    if( isset($user->ID) ) {
        delete_metadata("user", $user->ID, "changed_password");
    }
}

And in change-password.php I have:

<form action="" type="POST">
<label>Password</label>
<input type="password" name="new_pass" id="new_pass">
<input type="submit" value="Submit">
</form>
<?php
require(ABSPATH.'/wp-load.php');
$new_pass = $_POST['new_pass'];
$user_id = get_current_user_id();
$user_login = get_userdata($user_id);
$user_login = $user_login->user_login;

wp_update_user(array('ID' => $user_id, 'user_pass' => $new_pass));
wp_redirect(home_url());

Can anyone tell me why this is not working? It updates the database with a blank value in the user_pass section and upon hitting submit i get the error message: Warning: get_object_vars() expects parameter 1 to be object, null given in /Applications/MAMP/htdocs/wordpress/xchange/wp-includes/user.php on line 1404

and it does not redirect

Thank you in advance

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